Functional Advantages

Design benefits

Beyond its cost and aesthetic advantages, the composite elevated tank offers some unique functional benefits:

The efficient use of materials, with concrete in compression and the tensile strength of steel for watertight containment
The efficient transmission of loads, with the steel tank transferring the weight of the water to the concrete ring beam and pedestal
Maintenance-free support
A strong structural roof with easy access
And dry, protected space inside the pedestal for a variety of multiple use options

Pedestal

The concrete pedestal of the composite elevated tank is exposed only to the seasonal variations of weather, a mild exposure in comparison to the aggressive environment associated with other successful structural concrete applications such as roads, bridges and hydraulic structures. The concrete pedestal provides excellent durability and, aside from the power washing of environmental effects where local conditions dictate, requires no maintenance.

The Landmark composite tank utilizes a concrete dome to support the steel tank floor within the pedestal. Thermal gradients, material properties and geometry prevent condensation from forming on the underside and dripping below, unlike steel tank styles which require a condensate ceiling and seal welding of interior lap seams. Landmark also provides galvanized ladders, landings, and other appurtenances within the concrete support pedestal, and the riser and overflow piping in this area is typically stainless steel. Painting, and the related maintenance it entails, is not required.

Steel Tank

The processes and controls employed by Landmark's coatings experts are the key to minimizing maintenance requirements on the steel tank. Improper surface preparation and coatings application is the most significant factor with regard to premature coatings failure. Coatings are workmanship sensitive, and there is no substitute for quality and care, particulalry when compared to the cost of additional coatings requirements over the life of the structure.

The vapor zone above the water level in a tank is an aggressive environment for corrosion, which does not benefit from the use of cathodic protection (if installed). Landmark provides full seal welding of interior roof support stiffeners to prevent "rust bleeding". Flanged roof stiffeners are a minimum 10 inch depth in order to provide reasonable access for coatings.

Multiple use options and appurtenances

Many municipalities take advantage of the pedestal interior for obvious applications such as equipment or vehicle storage and pump stations, but others have added not-so-obvious solutions:

Chlorination facilities
Secure document storage on several levels
Satellite fire stations
Emergency response stations
Water system monitoring and control operations
Office space finish-outs with multiple floors, elevators, and a full complement of windows

Inside and out, Landmark can include additional piping systems; access ladders, landings, platforms and hatches; safety and feature lighting; fall protection; freeze protection where required…as well as income generating assets such as cellular antenna systems integrated at the design stage. Landmark can also work with you to address emerging opportunities to “green” municipal infrastructure with water recycling and power generation programs.

For more examples of the possibilities, visit the Special interest projects section.

The more you know about composite elevated tanks, the clearer your decision will be—based on a compelling combination of functional, economic and aesthetic benefits.

Need convincing? Check out these expert commentaries.